In general, movable storage devices like multimedia cards (MMC), secure digital (SD) memory cards, compact flash (CF) cards, and memory sticks are used in movable digital devices (i.e. hosts) like camcorders, digital cameras, PDAs (personal digital assistance), and MP3s (MPEG-1 Layer 3). The devices communicate with the hosts in different protocols. Therefore, each movable storage device may only be connected to a host that communicates in a corresponding communication protocol.
Thus, as shown in FIG. 1, for a host that uses a specific protocol, a memory card that supports the specific protocol is used. In other words, a MultiMedia Card (MMC) 12 is used for an MMC host 11, and a Secure Digital (SD) memory card 14 is used for an SD host 13. Likewise, a Compact Flash (CF) card 16 is used for a CF host 15 and a universal serial bus (USB) apparatus 18 is used for a USB host 17. U.S. Pat. No. 6,388,919 discusses such card-type flash memory devices.
In order for a mobile storage device to be used with a host that has a specification different from that of the mobile storage device, the mobile storage device should have a specification that is in accordance with the host, have an interface apparatus dedicated for the host, or have an additional device that converts its communication protocol into a communication protocol of the host.
Although an interface function may be provided for the host or an additional device may be used in the mobile storage device, the mobile storage device may need to recognize the host type and determine an operation mode for interfacing the host. It is known to include an additional signal pin on the mobile storage device wherein the host outputs a control signal used for determining the operation mode for interfacing the host through the signal pin. However, this approach may increase the number of signal pins on the mobile storage device and may require that the host output the control signal to the mobile storage device.